Thiosulfate surfactant



THIOSULFATE SURFACTANT Edward L. Doerr, Dayton, hio, assignor to Monsanto Chemical Company, St. Louis, M0,,- a corporation of Delaware I No Drawing. Application May 21, 1958 Serial N0. 736,689

1 Claim. (Cl. 260-453) The present invention relates to surfactants and more particularly provides alkali metal thiosulfates as new compounds which possess a high degree of utility as detersive and lathering agents.

, 2,934,553 Patented Apr. 26, 1960 solids which, as hereinbefore stated are particularly value I able in that they possess an unusual combination of detersive, lathering and wetting-out properties. They thus find wide application in a large number of industrial processes, especially in those relating to the treatment of textiles,1leather and other fibrous materials. They are particularly valuable for laundering and in dishwashing In my application, Serial No. 599,347, filed July 23, a.

1956, now US. Patent No. 2,892,86l, I have disclosed alkali metal or ammonium salts of branched chain alkyl thio'sulfates having from 12 to 16 carbon atoms in the alkyl radical. While these branched chain compounds show especially low and therefore advantageous wettingout speeds when aqueous solutions thereof are tested by the Draves test, these products have been found to be somewhat deficient in detergency and lathering. I have now found that the heretofore unkno'wn metal salts of n-tridecyl thiosulfate are of outstanding value, not only for the purpose of assisting in .the'wetting of textile materials, but also because they possess outstanding detersive and lathering properties. They are particularly valuable as dishwashing agents.

The present salts of n-tridecyl thiosulfate are obtained by the reaction of an n-tridecyl halide with analkali metal thiosulfate substantially according to the scheme:

in which X is halogen andR is alkali metal.

The presently useful n-tridecyl halides include n-tridecyl bromide, n-tridecyl chloride and n-tridecyl iodide. The presently usefulinorganic thiosulfates include sodium, potassium or lithium thio'sulfates. Reaction of the n-trideeyl halide with the alkali metal thiosulfate takes place readily by heating a mixture of the two reactants at a in that they possess high cleansing and lathering efii ciency in both hard and soft water as well as in the presence of fatty solids; The invention is further illustrated, but not limited, by the following examples:

Example 1 A mixture consisting of 105.3 g. (0.4 mole) of n-tridecyl bromide, 129.0 g. of sodium thiosulfate pentahydrate, 300g. of ethanol and 100 g. of water was charged to a l-liter reactor which was equipped with stirrer, thermometerfan'cl reflux condenso'r. to refluxing temperatures and refluxing was continued for a total of 6.hours. The resulting reaction mixture was allowed to cool and stratify. Most of the lower, aqueous layer was removed with a pipette. Then after stripping the solvent from the residue, isopropanol was added to the stripped residue to replace saidsolvent, and the resulting mixture was filtered while hot to remove inorganic salts. The crystals which were obtained from the filtrate upon cooling were filtered off and dissolved in hot water. The resulting solution was treated with a filter aid, filtered and the filtrate cooled to give crystals of the product. Recrystallization from water and drying for 20 hours in a vacuum oven at 40 C. gave 64.9 g. of the snow white crystalline sodium n-tridecyl thiosulfate.

Example 2 This example provides a comparison of the surfactant. properties of the sodium n-tridecyl thiosulfate of Example 1 with those of other sodium alkyl thiosulfates.

temperature of, say, from C. to 150 C. in the presence or absence of an inert diluent or solvent. Refiuxing temperatures are preferred. For smooth reaction a liquid diluent is generally recommended. Conveniently this may be a mixture of solvents for the inorganic and organic constituents of the reaction mixture, e.g., a mixture of water and an organic liquid such as ethanol, isopropanol, benzene, acetone, ethyl ether, etc. The by-product alkali metal halide is readily removed from the reaction mixture either by decantation and/or alternate concentration, dissolution and precipitation. The residue comprises the alkali metal n-tridecyl thiosulfate and solvent in case it was employed as well as alkyl halide if an excess of said halide had been used. The solvent and alkyl halide may be readily removed'by distillation or by other appropriate means known to those skilled in the art.

The present alkali metal n-tridecyl thiosulfates are stable, well characterized crystalline to somewhat waxy Testing of the detersive efiiciency of the compounds shown below was conducted by the method described by Jay C. Harris and Earl L. Brown in the Journal o'fthe Detergencv. percent of GardinoP' in water Sodium Alkyl 'lhlosultate Tested hardness of- 50 p.p.m. 300 p.p.m.

n-Tridecyl -Q us Branched TrideeyL. 72 71 n-Dodecyl 83 65 2-Butyloctyl 78 74 In the above table, the branched tridecyl radical is the tridecyl radical derived from the branched chain tri The whole was brought" decanol prepared according to the OX0 process by the hightemperature, high pressure reaction of carbon monoxide and hydrogen with propylene tetramer or butylene. From the above tests, it is evident that in water of both 50 ppm. and 300 ppm. hardness, the sodium n-tridecyl thio'sulfate is significantly superior in dctersive efficiency to either said sodium branched tridecyl thiosulfate, the n-dodecyl thiosulfate, or the Z-butyloctyl thiosulfate.

Testing of the wetting-out properties by the Draves test of the American Association of Textile Colorists gave the following results:

Speed of Wetting, Seconds at Percent Sodium Alkyl Thiosultate Tested Concentration deflate-ti Er. 1) -Q 20. 7 37. 9 Branched tridecyl 1 22. 6 180+ n-Dodecyl 27. 3 180 Z-Butyloctyl- 180+ i The same compound used in detergent .tests above.

Sodium Alkyl Thiosulfate Tested At Once After 5 Min.

n-Tridecyl (Ex. 1) 20.0 19. 2 Branched trideeyl 14. 8 3. 3 nodecyl 13. 2 5.0 Z-Butyloctyl 4. 2 trace 1 The branched tridccyl radical which is derived from the branched chain tridecenol obtained according to the 0x0 process by the high pressure reaction of propylene tetramer or butylene trimer with carbon monoxide and hydrogen. 7

The above data show that of the above very closely related compounds, only the sodium n-tridecyl thiosulfate gives a stable, high foam.

This application is a co'ntinuation-in-part of my copending application, Serial No. 599,348, filed July 23, 195 6, and now abandoned.

What I claim is:

Sodium n-tridecyl thiosulfate.

References Cited in the file of this patent UNITED STATES PATENTS 1,969,612 Kaiser etal. Aug. 7, 1934 FOREIGN PATENTS 417,930 Great Britain Oct. 16, 1934 OTHER REFERENCES Niven, Jr.: Fundamentals of Detergency, 1950, p. 50. 

